Measuring arm with multifunctional end

ABSTRACT

A three-dimensional measuring device, comprising an arm having a free end provided with an interface body carrying a measuring member and a grip member enabling an operator to point the measuring member at a zone of the object that is to be measured. The measuring member includes a connector to be electrically connected to a corresponding connector of the interface body by a fastener mechanism that is controllable by a lever and that is arranged in such a manner that the lever controls the fastener mechanism to occupy selectively a snap-fastening state in which the measuring member is held on the interface body while the connectors are disengaged from each other, a locking state in which the measuring member is fastened to the interface body and the connectors are engaged with each other, or a release state in which the measuring member can be separated from the interface body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/EP2019/068032, filed Jul. 4, 2019, which claims priority to andthe benefit of French Patent Application No. 18 56250, filed Jul. 6,2018. The entire contents of each application are incorporated herein byreference in their entirety.

FIELD

The present invention relates to the field of metrology, and moreparticularly to measuring three-dimensional objects.

BACKGROUND

A three-dimensional measuring device generally comprises an arm made upof articulated elements including a fastener base, a first segmentconnected to the base by a first hinge, a second segment connected tothe first segment by a second hinge, an interface body connected to thesecond segment by a third hinge, and position sensors associated withthe hinges and electrically connected to an electronic acquisition unitfor supplying the electronic acquisition unit with position measurementsignals measuring the positions of the segments relative to one another.The interface body carries a measuring member and a handle enabling anoperator to point the measuring member at a zone of the object that isto be measured.

The measuring member may be of the contact type or of the contactlesstype. A contact measuring member is a touch probe that is to be appliedagainst said zone of the object. A contactless measuring member may be:a transmitter for transmitting an incident wave and a receiver forreceiving a reflected wave reflected by said zone of the object,enabling a measurement to be made from the time lapse betweentransmitting the incident wave and receiving the reflected wave; or anoptical device for capturing an image associated with a projector forprojecting a light pattern to enable measurements to be calculated byprocessing the image of the light pattern projected onto the zone thatis to be measured; or a combination of the above two techniques.

The handle is generally of the “pistol-grip” type. When the measuringmember is of the contactless type, the handle is usually fitted with atleast one button controlling a switch that is connected by an electricalcircuit to the control unit so as to enable the operator to causemeasurement signals to be acquired by using the hand that is holding thehandle and pointing the measuring member. When the measuring member isof the contact type, the handle may be fitted as above with a button forcontrolling acquisition, or the switch may be controlled directly by thetouch probe as a function of the force being applied by the touch probeon the zone of the object that is to be measured.

An object of the invention is to provide means for improving thefunctions of such a measuring device.

SUMMARY

To this end, the invention provides a three-dimensional measuringdevice, comprising an arm made up of articulated elements including afastener base, a first segment connected to the base by a first hinge, asecond segment connected to the first segment by a second hinge, aninterface body connected to the second segment by a third hinge, andposition sensors associated with the hinges and electrically connectedto an electronic acquisition unit for supplying the electronicacquisition unit with position measurement signals measuring thepositions of the elements relative to one another. The interface bodycarries a measuring member and a grip member enabling an operator topoint the measuring member at a zone of the object that is to bemeasured. The measuring member includes a connector to be electricallyconnected to a corresponding connector of the interface body by afastener mechanism that is controllable by a lever and that is arrangedin such a manner that the lever controls the fastener mechanism tooccupy selectively a snap-fastening state in which the measuring memberis held on the interface body while the connectors are disengaged fromeach other, a locking state in which the measuring member is fastened tothe interface body and the connectors are engaged with each other, or arelease state in which the measuring member can be separated from theinterface body.

Other characteristics and advantages of the invention appear on readingthe following description of particular, nonlimiting embodiments of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the accompanying drawings, in which:

FIG. 1 is a perspective view of a measuring device of the invention;

FIG. 2 is a perspective view of an interface body forming a free end ofthe arm of the measuring device;

FIG. 3 is an exploded perspective view of a first grip member of theinterface body;

FIG. 4 is a perspective view of the first grip member and of theinterface body before mounting;

FIG. 5a is an exploded perspective view of a second grip member of theinterface body;

FIG. 5b is a fragmentary perspective view of the fastener support of thesecond grip member;

FIG. 6 is a perspective view of the interface body fitted with two gripmembers and with a first measuring member;

FIG. 7 is a detailed view of FIG. 6 before putting the first measuringmember into place;

FIG. 8 is a perspective view of the interface body fitted with the firstgrip member only and with the first measuring member;

FIG. 9 is a perspective view of a second measuring member and of theinterface body before mounting;

FIG. 10 is a perspective view of the second measuring member and of theinterface body while they are being mounted on the free end of the arm;

FIG. 11 is a perspective view of the assembly mechanism for assemblingtogether the second measuring member and the interface body;

FIGS. 12 a, b, c, d, and e show the coupling and uncoupling operations;

FIGS. 13 a, b, and c show in transparency the various positions of theportion of the assembly mechanism carried by the second measuringmember;

FIG. 14 is a perspective view of the second measuring member mounted onthe free end of the arm;

FIG. 15 is a detail view of the front portion of the interface body;

FIG. 16 is a section view of the remote measuring member on plane XVI ofFIG. 12 a;

FIG. 17 is a perspective view of the interface body fitted with anadapter support for carrying a third measuring member;

FIG. 18 is a perspective view of the interface body with the adaptersupport for carrying a third measuring member while it is being mounted;

FIG. 19 is a perspective view of the interface body fitted with theadapter support, the third measuring member, and a fourth measuringmember;

FIG. 20 is a longitudinal section view of the interface body;

FIG. 21 is an exploded perspective view of a coupling interface, andmore particularly of a tubular coupling part, of the first measuringmember; and

FIG. 22 is a perspective view of this coupling interface.

DETAILED DESCRIPTION

With reference to the figures, the three-dimensional measuring device ofthe invention comprises an arm made up of articulated elements.

The articulated elements comprise a fastener base 10, a first segment 11connected to the base 10 by a first hinge 21, a second segment 12connected to the first segment 11 by a second hinge 22, and an interfacebody 100 connected to the second segment 12 by a third hinge 23.

The first hinge 21 and the second hinge 22 are double hinges allowingthe elements that they connect together to pivot relative to each otherabout two mutually perpendicular axes. The third hinge 23 is a triplehinge allowing the second segment 12 and the interface body 100 to pivotrelative to each other about three axes, one of which is substantiallyperpendicular relative to the others (the three axes being referenceda1, a2, and a3 in FIG. 2). Each axis of the hinges 21, 22, and 23 isassociated with position sensors that are not visible in the figures andthat are electrically connected to an electronic acquisition unit 1000for supplying the electronic acquisition unit 1000 with measurementsignals measuring the angular positions of the elements relative to oneanother. Each of the sensors may be connected to the acquisition unit1000 by a respective cable pair, or they may all be connected togetherby a bus. By way of example, the acquisition unit may be a computer, andin particular a laptop computer, that is connected by a connector ofuniversal serial bus (USB) or other type to a corresponding connectoraccessible from outside the base 10. The computer executes athree-dimensional measurement program that is itself known. The base 10advantageously incorporates an electronic circuit connected to a screenand arranged to supply the operator with information about the operatingstate of the arm.

The interface body 100 comprises a rigid structure 101 having a cover102 mounted thereon in such a manner that a space 103 exists between thestructure 101 and the cover 102 (see more particularly FIG. 20).

The interface body 100 is provided with a display device 2000electrically connected to an electronic circuit 2001, itselfelectrically connected to the electronic acquisition unit 1000 by adedicated line. The display device 2000 is fitted with amultidirectional button 2002 that is electrically connected to theelectronic circuit 2001 in order to make selections in menus that aredisplayed by the display device 2000. The electronic circuit 2001extends in the space 103 that exists between the structure 101 and thecover 102.

With reference more particularly to FIG. 15, the interface body 100 has:a front face 104 arranged to form a fastener plate for fastening eitherto a first grip member 200 or else to a remote measuring member 400; atubular coupling part 110 for coupling to a contact measuring member 500projecting from said front face 104; and also a side surface 105arranged to form a second fastener plate for fastening to a second gripmember 300.

The tubular coupling part 110 is provided with two external projections111 that are positioned symmetrically relative to each other.

Electrical connectors 120 are accessible in the front face 104 forconnecting to the remote measuring member 400.

With reference more particularly to FIGS. 3 and 4, the first grip member200 comprises an annular grippable body 201 having a central cylindricalduct 202 enabling the annular grippable body 201 to be engaged on thetubular coupling part 110 so that the annular grippable body 201 extendsover the front surface 104 and the electrical connectors 120. Thecentral cylindrical duct 202 is provided with two axial grooves 203 forreceiving the external projections 111.

A retaining element 204 is mounted on the annular grippable body 201 toslide transversely relative to the tubular coupling part 110. Theretaining element 204 is in the shape of a fork with two branches 205and it is mounted on the annular grippable body 201 between:

-   -   a retaining position in which the branches 205 have respective        portions projecting into the axial grooves 203 in order to be        engaged behind the external projections 111 so as to press the        annular grippable body 201 against the front face 104; and    -   a release position in which the branches 205 have respective        notches coinciding with the axial grooves 203 so as to allow the        external projections 111 to pass through. The branches 205 have        wedge-forming surfaces so as to hold the annular grippable body        201 clamped against the front face 104. The retaining element        204 is held in each of its positions by a ball that is mounted        in a housing of the retaining element 204 to be movable between        a retracted position inside the housing and a projecting        position into which it is urged resiliently and in which it        projects from the housing. The annular grippable body 201 is        provided with two setbacks positioned to receive the projecting        ball respectively when the retaining element 204 is in its        release position and in its retaining position. In a variant, it        is possible merely to provide a spring mounted between the        annular grippable body 201 and the retaining element 204 so as        to urge the retaining element 204 resiliently into its retaining        position.

The annular grippable body 201 has an outside surface front portion 206that is curved and an outside surface side portion 207 in which at leastone button 208 is accessible for actuating a switch received inside theannular grippable body 201. The switch is connected to a connector 209carried by the annular grippable body 201 so as to be connected to oneof the electrical connectors 120 when the annular grippable body 201 ispressed against the front face 104. The outside surface front portion206 is substantially in the shape of a spherical cap. It should beobserved that the connectors 209 and 120 being connected together makesit possible to detect that the annular grippable body 200 is present. Itis thus possible, in all or part of a measurement protocol, to preventpoints being measured if the annular grippable body 200 is not mounted.

With reference more particularly to FIGS. 5a, 5b , and 6, the secondgrip member 300 has a handle 301 of “pistol-grip” type. The handle 301is secured to a fastener base 600 having a reinforcing appendix 601 onwhich the handle 301 is engaged, and an end portion 602 having aslideway 603 that extends transversely relative to a longitudinaldirection of the reinforcing appendix 601 in order to co-operate with aslideway 114 of the side surface 105 of the interface body 100. Theinterface body 100 and the end portion 602 of the fastener support 600include complementary abutment means so as to define a position in whichthe slideways 603 and 114 are mutually engaged, and complementarylocking means opposing disengagement of the slideways 603 and 114. Thecomplementary locking means comprise a control lever 604 that is hingedon the end portion 602 of the fastener base 600 between an activationposition for activating the locking means and an inactivation positionfor inactivating the locking means. The control lever 604 is U-shapedwith two branches having their free ends secured to respective ends of ashaft 605 that is provided with a lug 606 and that is pivotally mountedon the end portion 602 of the fastener base 600. The fastener support600 is provided with a rocker latch 607 having a first end pivotallymounted in the end portion 602 so as to have a second end that ismovable between a retracted position and a projecting positionprojecting from the end portion 602. A link 608 is hinged at one end tothe lug 606 and at the other end to the rocker latch 607 in such amanner that when the control lever 604 is in its activation position,the rocker latch 607 is in its projecting position to co-operate with anabutment of the side surface 105 of the interface body 100 and opposesdisengagement of the slideways 603 and 114, and when the control lever604 is in its deactivation position, the rocker latch 607 is in itsretracted position away from the abutment and allows the slideways 603and 114 to be disengaged.

The handle 301 is tubular in shape with a grippable outside surface 302and an inside surface 303 defining a housing in which the reinforcingappendix 601 is engaged. The handle 301 is fastened on the reinforcingappendix 601 of the fastener base 600 by at least one screw 609 passingthrough an end wall of the handle 301 to be engaged in a tapped hole 610in a free end portion 611 of the reinforcing appendix 601 of thefastener base 600 extending facing the end wall. The device of theinvention advantageously includes a set of interchangeable handles 301of different outside dimensions adapted to hands of different sizes.

Said end portion 602 of the fastener base 600 includes both anacquisition control button 612 (in the form of a trigger) for actuatinga switch that is electrically connected to a connector 613 forconnection to a connector that is accessible in the side surface 105 andthat is electrically connected to the electronic acquisition unit 1000,and also a multidirectional selector button 614 for actuating a switchthat is also electrically connected to the connector 613. The handle 301itself does not have any electronic circuit portion or an electroniccomponent. The same applies to the reinforcing appendix 601.

With reference more particularly to FIG. 15, the contact measuringmember 500 comprises a touch probe 501 carried by a male cylindricalportion 502 engaged in a tubular coupling part 110 secured to theinterface body 100. The male cylindrical portion 502 and the tubularcoupling part 110 form two separable portions of a coupling interface.The tubular coupling part 110 is provided with a locking mechanism,given overall reference 1100, for locking the coupling and comprising atab 112 formed by a curved plate and carried by a pin 115 mounted on thetubular coupling part 110 to pivot about a radial direction of thetubular coupling part 110 between a retaining position for retaining themale cylindrical portion 502 and a release position for releasing themale cylindrical portion 502. The tab 112 is also mounted on the tubularcoupling part 110 to pivot between a position in which it is pressedagainst an outside surface 113 of the tubular coupling part 110 and araised position enabling it to be handled.

With reference more particularly to FIGS. 20 to 22, in this example thelocking mechanism 1100 housed in the tubular coupling part 110 is of thesame type as that described in document U.S. Pat. No. 7,282,017. Thelocking mechanism 1100 comprises a slider 1101 defining a receptionhousing 1102 for receiving a stem 503 of the male cylindrical portion502 and two pins 1103 (although one would suffice) extending facing eachother on either side of the housing 1102. The pins 1103 have mutuallyparallel axes that are contained in a common plane transverse to thehousing 1102, and they are mounted in the slider 1101 to be movablebetween a locking position in which the pins 1103 have respectivecentral portions projecting into the housing 1102, and an unlockingposition in which the central portions of the pins 1103 are retractedout from the housing 1102. The pins 1103 have ends that are received intwo transverse grooves 1104 made in diametrically opposite positions inthe inside surface of an insert 1105 fastened in the tubular couplingpart 110. The insert 1105 comprises two portions touching each otheralong a join plane containing the central axis of the tubular couplingpart 110, said portions being symmetrical about the join plane, and eachportion including a respective one of the grooves 1104 for receiving theends of the pins 1103. Each pin 1103 also possesses two intermediateportions each extending between a respective one of the ends of said pinand the central portion of said pin, and received in respective slots1106 formed in the slider 1101 so as to extend in sloping mannerrelative to the central axis of the tubular coupling part 110. Theslider 1101 is mounted in the insert 1105 to slide parallel to thecentral axis of the tubular coupling part 110 between the first andsecond positions, and the slope of the slots 1106 is determined so thatmoving the slider 1101 from its first position to its second positioncauses the pins 1103 to move from their locking positions to theirunlocking positions, and vice versa. The pin 115 having the tab 112secured to one of its ends has an opposite end that is engaged in a hole1107 formed in the insert 1105. Between its two ends, the pin 115 has anoff-center portion received in a groove 1108 formed in the slider 1101to extend transversely to the central axis of the tubular coupling part110 in such a manner that pivoting the tab 112 from its retainingposition to its release position causes the slider 1101 to move from itsfirst position to its second position, and vice versa. The pin 115 ofthe tab 112 passes through the wall of the tubular coupling part 110 andthrough the insert 1105, and it possesses a groove fitted with anannular sealing gasket 117 that co-operates with the wall of the tubularcoupling part 110 to provide sealing between them.

The male cylindrical portion 502 has a transverse face 504 from whichthere projects the stem 503 that is to be inserted into the housing 1102of the slider 1101 and that is provided with two notches to receive thecentral portions of the pins 1103 when they are in their lockingposition. The transverse face 504 is provided with a sealing gasket 505in the form of a peripheral elastomer lip that projects from saidtransverse face 504 so as to be deformed and pressed against a planeannular surface 118 of the free end of the tubular coupling part 110,thereby providing sealing between the tubular coupling part 110 and themale cylindrical portion 502.

In this example, the sealing gaskets 117 and 505 are arranged to complywith the IP54 standard. It should be observed that the ability to folddown the tab 112 onto the tubular coupling part 110 presents threeadvantages. Specifically, when it is in the folded-down position, thetab 112:

-   -   does not impede handling of the interface body 100 for        performing measuring operations;    -   does not impede installation of the first grip member 200 or of        the second measuring member 400 for remote measuring; and    -   opposes turning about the radial direction of the tubular        coupling part (the curved portions of the tab 112 come into        abutment against the outside surface of the tubular coupling        part).

The remote measuring member 400 comprises a frame 401, an opticalsensor, and a projector for projecting a light pattern. The remotemeasuring member 400 is for pointing at a zone of the object that is tobe measured in order to project the light pattern thereon and take animage. The operating principle of the remote measuring member 400 isitself known and is not described in detail herein.

With reference more particularly to FIGS. 11 to 13 and 16, the frame 401of the remote measuring member 400 includes an orifice 402 for passingthe tubular coupling part 110 and connectors 403 for being electricallyconnected to the connectors 120 of the interface body 100. The frame 401is designed to be connected to the interface body 100 by a fastenermechanism 700 that can be selectively controlled to occupy asnap-fastening state (FIGS. 12a, 12c, 13c ) in which the remotemeasuring member 400 is held on the interface body 100 while theconnectors 403 and 120 are disengaged from each other, a locking state(FIGS. 11, 12 b, 13 a) in which the remote measuring member 400 isfastened to the interface body 100 and the connectors 403 and 120 areengaged in each other, and a release state (FIGS. 12d, 12e, 13b ) inwhich the remote measuring member 400 can be separated from theinterface body 100.

The fastener mechanism 700 has two projections 701 arrangedsymmetrically on either side of the tubular coupling part 110 and eachformed by a bar passing through a housing formed in the front face 104.

The locking mechanism has two hooks 702 mounted on the frame 401 of theremote measuring member 400 symmetrically on either side of the orifice401 to tilt about a tilt axis A1 between a locking position and anunlocking position. Between each hook 702 and the frame 401, thereextends a resilient return element 703 for urging the hook 702 towardsthe locking position.

The hooks 702 of the locking mechanism 700 are controlled by a lever 704in the shape of a fork with branches 705, each having a free end hingedto the frame 401 of the remote measuring member 400. The free end ofeach branch 705 of the lever 704 is hinged to the remote measuringmember 400 about a pivot axis A2 distinct from the tilt axis A1 of thehook 702 and that is constrained to rotate with an eccentric 706received in a housing 707 of the hook 702 in such a manner that:

-   -   when the lever 704 is in a locking position (FIG. 12b ), each        eccentric 706 bears against a bottom surface of the housing 707        and holds the hook 702 in its locking position (FIG. 13a );    -   when the lever 704 is in an unlocking position (FIGS. 12d, 12e        ), each eccentric 706 bears against a top surface of the housing        707 and holds the hook 702 in its unlocking position (FIG. 13b        ); and    -   when the lever 704 is in a snap-fastening position (FIGS. 12c,        13c ), each eccentric 706 is in the top portion of the housing        707 so as to avoid impeding movement of the hook between its two        positions so as to leave the hook 702 in a snap-fastening state.        In this state, the hook is free to be moved between its two        positions (FIG. 13c ).

The snap-fastening position of the lever 704, i.e. its positioncorresponding to the snap-fastening state, is situated between the othertwo positions of the lever 704.

With reference more particularly to FIGS. 17 to 19, the measuring deviceincludes a fastener support 800 for fastening a third measuring member900. In this example, the third measuring member 900 is a contactlessmeasuring member provided with a battery and with wireless connectionmeans for connection with the electronic acquisition unit 1000. In avariant, it is possible to provide an external wired link between thethird measuring member 900 and the electronic acquisition unit 1000. Theoperating principle of the remote measuring member 900 is itself knownand is not described in detail herein.

The fastener support 800 comprises a body 801 having two housings 802and 803 made therein and opening out into opposite faces of the body801. In this example, the fastener support 800 is fastened to theinterface body by using a mechanism similar to that used for fasteningthe grip body 200. The housing 802 is of dimensions such that an endwall of the housing 802 can be pressed against the front face 104, andthe side walls of the housing 802 cover a portion of the outside surfaceof the interface body 100 adjacent to the front face 104. The housing803 is of dimensions suitable for enabling a portion of a connector tobe fastened thereto for connecting to the third measuring member 900. Inthis example, the housing 803 is provided with a male portion analogousto the male portion 502 that co-operates with the tubular coupling part110, while the third measuring member is provided with a tubularcoupling part identical to the tubular coupling part 110. In operation,the operating support 800 is positioned so that the third measuringmember 900 extends under the tubular coupling part 110 so that theassembly constituted by the interface body 100, the fastener support800, and the third measuring member 900 is more comfortable for theoperator to handle.

It can be seen in FIG. 19 that the measuring device is fitted with afourth measuring member that is a contact measuring member 550comprising a touch probe 551 carried by a male cylindrical portion 552engaged in the tubular coupling part 110 secured to the interface body100. The contact measuring member 550 takes the place of the contactmeasuring member 500 when it is desired to take measurements both bycontact and also by means of the third measuring member 900. The contactmeasuring member 550 is characterized in that it is longer than thecontact measuring member 500 so that the touch probe 551 can be put intocontact with the object that is to be measured while limiting any riskof contact between the third measuring member 900 and said object thatis to be measured.

It should be observed that, in the preferred embodiment describedherein, the device of the invention has six main characteristics:

1) the measuring member is connected to the interface body by a fastenermechanism that is controllable by a lever and that is arranged in such amanner that the lever controls the fastener mechanism to occupyselectively a snap-fastening state in which the measuring member is heldon the interface body while the connectors are disengaged from eachother, a locking state in which the measuring member is fastened to theinterface body and the connectors are engaged with each other, or arelease state in which the measuring member can be separated from theinterface body;

2) the handle is tubular in shape with a grippable outside surface andan inside surface that defines a housing in which there is engaged areinforcing portion of a fastener base, which portion has an end portionthat projects from the handle and that is fastened to the interfacebody;

3) the handle is secured to a fastener base having an end portion thatincludes a slideway extending transversely relative to the longitudinaldirection of the handle in order to co-operate with a slideway of theinterface body, the interface body and the end portion of the fastenersupport having both complementary abutment means so as to define amutual engagement position of the slideways and also complementarylocking means that oppose disengagement of the slideways, thecomplementary locking means including a control lever that is hinged tothe end portion of the fastener base between an activation position foractivating the locking means and an inactivation position forinactivating the locking means;

4) the interface body includes a front face that has projectingtherefrom a tubular coupling part for coupling to a first measuringmember for measuring by contact and that is arranged to form a fastenerplate for fastening either to a first grip member or else to a remotemeasuring member, and the interface body also includes a side surfacearranged to form a second fastener plate for fastening to a second gripmember;

5) the interface body has a front face in which at least one electricalconnector is accessible and from which there extends a projectingtubular coupling part for coupling to the measuring member, an annulargrippable body being engaged on the tubular coupling part and extendingover the front surface and the electrical connector, a wedge-formingretaining element being mounted on the grippable body to slidetransversely relative to the tubular coupling part and to be engagedbehind an external projection of the tubular coupling part in order tohold the grippable body pressed against the front face of the interfacebody; and

6) the measuring member comprises a male cylindrical portion engaged ina tubular coupling part secured to the interface body, the tubularcoupling part is provided with a coupling locking mechanism comprising atab formed by a curved plate and mounted on the tubular coupling portionso as to be capable of pivoting from a position pressed against theoutside surface of the tubular coupling part and a raised positionenabling it to be operated.

Characteristic 1 is particularly advantageous in that it makes it easierto put the measuring member into place, which member can be relativelyheavy and/or bulky. The measuring member is put into place while themechanism is in its snap-fastening state, thereby enabling the measuringmember to be attached to the interface body without the operator needingto act on the lever, merely by engaging the measuring member on thetubular coupling part until they are snap fastened. Once the measuringmember is attached to the interface body, the operator can proceed withfiner movements to connect the connectors and then to prevent themeasuring member from moving relative to the interface body by causingthe fastener mechanism to take up its locking state. The measuringmember is removed by putting the fastener mechanism into its releasestate prior to moving the measuring member away from the interface body.

Characteristic 2 is particularly advantageous in that it allows thehandle to be removed quickly, e.g. in order to be cleaned, repaired, orreplaced by a handle of different dimensions. The fact of having afastener support that is distinct from the handle also makes it possibleto place a button or an electronic circuit in the top portion of thefastener support, i.e. above the handle, so that the handle itself isinexpensive and can easily be replaced.

Characteristic 3 is particularly advantageous in that it allows the gripmember to be fastened relatively simply and quickly.

Characteristic 4 is particularly advantageous in that it allows forgreat flexibility in use of the arm of the measuring device.

Characteristic 5 is particularly advantageous in that it enables thefront surface of the interface body to be used as a zone for grippingthe interface body while providing the connector with protection so thatit is not subjected to impacts or to soiling.

Characteristic 6 is particularly advantageous in that the plate does notimpede handling of the interface body while taking measurements.

Naturally, the invention is not limited to the embodiments described andcovers any variant coming within the ambit of the invention as definedby the claims.

In particular, although the preferred embodiment of the measuring devicehas six main characteristics, the invention applies to measuring devicesthat do not have all of those characteristics, which characteristics canbe implemented independently of one another.

At least a portion of the electronic circuit may occupy all or part ofthe space that exists between the structure and the cover.

The acquisition unit 1000 may be incorporated in the base 10, which thenincludes a computer unit associated with a human-machine interface, e.g.including a keyboard and a screen.

The reinforcing appendix 601 is optional.

The tab 112 need not be in the form of a curved plate, for example itcould be in the form of a button.

The first annular sealing gasket mounted on the pin of the tab so as tobear against the surface of the tube coupling part may be of numerousshapes, for example it could be an O-ring, a lobe seal, or a lip seal.

The second annular sealing gasket mounted between the tubular couplingpart and the male cylindrical portion so as to be deformed between themwhen the male cylindrical portion is mounted in the tubular couplingpart secured to the interface body may be of some other shape, forexample it could be an O-ring.

The tab 112 is arranged to be movable about the axis of its pin betweena locking position and an unlocking position for the mechanism, with thetab 112 having an intermediate position in which the locking mechanismallows the male portion to be inserted and held resiliently withoutbeing locked. Different structures allowing other modes of operation arepossible. It is thus possible not to have a snap-fastening position.

The lever 704 may be of a shape other than that described, and forexample it could comprise only one branch. Also, the lever could bemounted to pivot or to slide.

The fastener mechanism controlled by the lever 704 may be of a structurethat is different from that described, and for example it could haveonly one hook. The snap-fastening position may be arranged on one sideor the other of the other two positions instead of lying between them.

Even though this is not the preferred embodiment, the handle 301 couldbe provided with at least one button and/or with at least one electroniccomponent.

The fastener base may be provided with one or more buttons and/or one ormore electronic components, or it may have none.

The handle 301 may be fastened to the fastener base 600 by means otherthan the screw 609, and for example it could be fastened by asnap-fastener mechanism or by a transverse pin passing through a portionof the handle 301 and a portion of the fastener base 600.

The reinforcing portion 601 may extend over all or part of the handle301.

The base 600 may be fastened to the interface body 100 by other means,e.g. by one or more screws, by a pin, etc.

The arm may be of a structure different from that described, e.g. havingsome other number of segments, hinges that are simple instead of beingdouble or double instead of being triple, and/or segments that aretelescopic . . . .

The interface body need not have a display and/or electronic circuits.

The lever 604 may be secured to a shaft 605 carrying a stud bearingagainst the rocker latch 607 in order to form a cam that moves therocker latch 607 between its two positions.

The measuring members may be touch probes of different shapes and/orsizes, for example they could be angled, having one or more pointingends of different shapes and/or sizes (e.g. spherical or conical) . . ..

The measuring members may be telemetric, e.g. optical and in particularstereoscopic, or laser (lidar type), etc.

The grippable body 200 may be fastened to the interface body 100 byother means, and for example by a nut screwed onto the tubular couplingpart 110, a pin engaged transversely in the grippable body 200 and thetubular coupling part 110, a sloping key engaged transversely in thegrip body 200 and the tubular coupling part 110 . . . .

The arm may be provided with one or more multifunction buttons and/orwith one or more single-function buttons.

The locking mechanism 1100 may have a structure other than thatdescribed, and for example it may comprise a hook that is movablebetween a locking position in which the hook is engaged in a ringcarried by the male portion, and an unlocking position in which the hookis disengaged from said ring.

What is claimed is:
 1. A three-dimensional measuring device, comprising:an arm made up of articulated elements including: a fastener base, afirst segment connected to the base by a first hinge, a second segmentconnected to the first segment by a second hinge, an interface bodyconnected to the second segment by a third hinge, and position sensorsassociated with the hinges and electrically connected to an electronicacquisition unit for supplying the electronic acquisition unit withposition measurement signals measuring the positions of the elementsrelative to one another, the interface body carrying a measuring memberand a grip member enabling an operator to point the measuring member ata zone of the object that is to be measured, wherein the measuringmember includes a connector to be electrically connected to acorresponding connector of the interface body by a fastener mechanismthat is controllable by a lever and that is arranged in such a mannerthat the lever controls the fastener mechanism to occupy selectively: asnap-fastening state in which the measuring member is held on theinterface body while the connectors are disengaged from each other, alocking state in which the measuring member is fastened to the interfacebody and the connectors are engaged with each other, or a release statein which the measuring member can be separated from the interface body.2. The device according to claim 1, wherein the lever has three stablepositions, each corresponding to a respective state of the fastenermechanism, the position of the lever that corresponds to thesnap-fastening state being situated between the other two positions. 3.The device according to claim 1, wherein the fastener mechanismcomprises at least one hook mounted on the measuring member to tiltabout a tilt axis between a locking position and an unlocking position,and a resilient return element for urging the hook towards the lockingposition.
 4. The device according to claim 3, wherein the lever has anend that is hinged to the measuring member about a pivot axis distinctfrom the tilt axis of the hook and that is connected to an eccentricreceived in a housing of the hook in such a manner that: when the leveris in the locking position, the eccentric bears against a surface of thehousing and holds the hook in the locking position, when the lever is inthe unlocking position, the eccentric bears against a surface of thehousing and holds the hook in the unlocking position, and when the leveris in the snap-fastening position, the eccentric is not engaged with anysurface of the housing and leaves the hook free to be moved between itstwo positions.
 5. The device according to claim 3, wherein two hooks aremounted symmetrically on the measuring member so as to be actuated bythe same lever.
 6. The device according to claim 5, wherein the lever isin the shape of a fork having branches with free ends that are hinged tothe measuring member.
 7. The device according to claim 1, wherein thefirst hinge and the second hinge are double hinges allowing the elementsthat they connect together to pivot relative to each other about twomutually perpendicular axes.
 8. The device according to claim 1, whereinthe third hinge is a triple hinge allowing the second segment and theinterface body to pivot relative to each other about three axes, one ofwhich is substantially perpendicular to the others.
 9. The deviceaccording to claim 1, wherein the interface body is provided with adisplay device and an electronic circuit that are electrically connectedto the electronic acquisition unit.
 10. The device according to claim 9,wherein the display device is fitted with a multidirectional button formaking selections in menus displayed by the display device.
 11. Thedevice according to claim 1, wherein the interface body comprises arigid structure over which there is mounted a cover in such a mannerthat there exists a space between the structure and the cover, at leasta portion of the electronic circuit extending in said space.
 12. Thedevice according to claim 1, wherein the measuring device includes afastener support for fastening a third measuring member.
 13. The deviceaccording to claim 12, wherein the fastener support comprises a bodyhaving two housings formed therein and opening out in opposite faces ofthe body, one of the housings having dimensions for receiving a frontportion of the interface body, and the other housing having dimensionsenabling a portion of the third measuring member to be fastened therein.